309 research outputs found
MUST learning through serving : academic service-learning model at Minghsin University of Science and Technology in Taiwan
AMP-Activated Protein Kinase Activation during Cardioplegia-Induced Hypoxia/Reoxygenation Injury Attenuates Cardiomyocytic Apoptosis via Reduction of Endoplasmic Reticulum Stress
Cardioplegic-induced H/R injury results in cardiomyocytic apoptosis. AMPK has been shown to reduce ER stress and the unfolded protein response (UPR). Whether AMPK activation can attenuate cardiomyocytic apoptosis after cardioplegia-induced H/R injury is unknown.
Cardiomyocytes were exposed to simulated ischemia by incubation in a hypoxic chamber with intermittent cold cardioplegia solution infusion at 20-minute intervals and subsequently reoxygenated in a normoxic environment. Various doses of AMPK activators (AICAR or metformin) were given 2 days before H/R injury. The cardiomyocytes were harvested after reoxygenation for subsequent examination.
With both AMPK activators, the antiapoptotic genes of ER stress and UPR, the subsequent production of proapoptotic proteins was attenuated, and the antiapoptotic proteins were elevated. The activity of the apoptotic effectors of ER stress was also reduced with AMPK activation. Moreover, TUNEL staining showed that AMPK activation significantly reduced the percentage of apoptotic cardiomyocytes after cardioplegia-induced H/R injury.
Our results revealed that AMPK activation during cardioplegia-induced H/R injury attenuates cardiomyocytic apoptosis, via enhancement of antiapoptotic and reduction of proapoptotic responses, resulting from lessening ER stress and the UPR. AMPK activation may serve as a future pharmacological target to reduce H/R injury in the clinical setting
Matrix metalloproteinase-3 promoter polymorphisms but not dupA-H. pylori correlate to duodenal ulcers in H. pylori-infected females
<p>Abstract</p> <p>Background</p> <p>This study investigated if the <it>H. pylori dupA </it>genotype and certain host single nucleotide polymorphisms (SNPs) of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs), including MMP-3, MMP-7, MMP-9, TIMP-1 and TIMP-2, might correlate with ulcer risk of <it>H. pylori-</it>infected Taiwanese patients.</p> <p>Results</p> <p>Of the 549 <it>H. pylori-</it>infected patients enrolled, 470 patients (265 with gastritis, 118 with duodenal ulcer, and 87 with gastric ulcer) received SNPs analysis of MMP-3<sub>-1612 6A > 5A</sub>, MMP-7<sub>-181 A > G</sub>, MMP-9<sub>exon 6 A > G</sub>, TIMP-1<sub>372 T > C </sub>and TIMP-2<sub>-418 G > C </sub>by PCR-RFLP. The 181 collected <it>H. pylori </it>isolates were detected for the <it>dupA </it>genotype by PCR. The rates of <it>dupA</it>-positive <it>H. pylori </it>infection were similar among patients with duodenal ulcer (22.8%), gastric ulcer (20.0%), and gastritis (25.5%) (<it>p </it>> 0.05). Males had higher rates of duodenal ulcer and gastric ulcer than females (<it>p </it>< 0.01). Of <it>H. pylori</it>-infected patients, the MMP-3 6A6A genotype were more common in patients with duodenal ulcers than in those with gastritis (87.7% <it>vs</it>. 74.9%, <it>p </it>< 0.05) in females. This genotype had a 2.4-fold (95% CI: 1.02-5.66) increased risk of duodenal ulcer, compared to those with the 5A carrier. Combining the MMP-3/TIMP-1 genotype as 6A6A/CC, the risk of duodenal ulcer increased up to 3.6 fold (<it>p </it>< 0.05) in <it>H. pylori-</it>infected females.</p> <p>Conclusions</p> <p>The MMP-3 promoter polymorphism, but not the <it>dupA</it>-status, may correlate with susceptibility to duodenal ulcer after <it>H. pylori </it>infection in Taiwanese females.</p
Decoupled Contrastive Learning
Contrastive learning (CL) is one of the most successful paradigms for
self-supervised learning (SSL). In a principled way, it considers two augmented
"views" of the same image as positive to be pulled closer, and all other images
as negative to be pushed further apart. However, behind the impressive success
of CL-based techniques, their formulation often relies on heavy-computation
settings, including large sample batches, extensive training epochs, etc. We
are thus motivated to tackle these issues and establish a simple, efficient,
yet competitive baseline of contrastive learning. Specifically, we identify,
from theoretical and empirical studies, a noticeable negative-positive-coupling
(NPC) effect in the widely used InfoNCE loss, leading to unsuitable learning
efficiency concerning the batch size. By removing the NPC effect, we propose
decoupled contrastive learning (DCL) loss, which removes the positive term from
the denominator and significantly improves the learning efficiency. DCL
achieves competitive performance with less sensitivity to sub-optimal
hyperparameters, requiring neither large batches in SimCLR, momentum encoding
in MoCo, or large epochs. We demonstrate with various benchmarks while
manifesting robustness as much less sensitive to suboptimal hyperparameters.
Notably, SimCLR with DCL achieves 68.2% ImageNet-1K top-1 accuracy using batch
size 256 within 200 epochs pre-training, outperforming its SimCLR baseline by
6.4%. Further, DCL can be combined with the SOTA contrastive learning method,
NNCLR, to achieve 72.3% ImageNet-1K top-1 accuracy with 512 batch size in 400
epochs, which represents a new SOTA in contrastive learning. We believe DCL
provides a valuable baseline for future contrastive SSL studies.Comment: Accepted by ECCV202
The Volcanic Earthquake Swarm of October 20, 2009 in the Tatun Area of Northern Taiwan
On October 20, 2009, a series of felt earthquakes with local magnitudes ranging from 2.8 - 3.2 occurred in the Tatun volcanic area off the northern tip of Taiwan. Although there was no damage caused by those earthquakes, many residents in the Taipei metropolitan area, particularly for people who live near the Yangminshan National Park, felt strong ground shaking. In order to know what the possible mechanisms were that generated those earthquakes, we carefully examined seismic data recorded by a dense seismic array in the Tatun volcanic area. During the period between October 18 and 22, 2009 we detected at least 202 micro-earthquakes. Most of the earthquakes were relocated using the double-difference method and were clustered in the shallow crust beneath the Dayoukeng area, which is the strongest fumarole in the Tatun volcanic area. Among these earthquakes, 72 focal mechanisms were determined by polarizing the first P-wave motion. Most earthquakes belonged to normal faulting. An extremely high b-value of 2.17 was obtained from those earthquakes. Based on the seismic variations in both the temporary and spatial distribution as well as an extremely high b-value, we conclude that the earthquake sequence on October 20, 2009 was a typically seismic swarm associated with possible active volcanism in the Tatun volcanic area
Integration of Chinese Herbal Medicine into Routine Care Was Related to Lower Risk of Chronic Kidney Disease in Patients with Rheumatoid Arthritis: A Population-Based Nested Case–Control Study in Taiwan
Objective
Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used as the first-line agents for the symptomatic relief of rheumatoid arthritis (RA), but it may insidiously provoke the onset of renal diseases, especially chronic kidney disease (CKD). While Chinese herbal medicine (CHM) has become an increasingly popular adjunctive therapy among RA groups, there are currently no available data on the effect of CHM use towards risk of CKD. This study aimed to explore on a population-level whether CHM use decreases sequent CKD risk among them. Methods
In this nested case–control study retrieved from the nationwide insurance database of Taiwan from 2000 to 2012, we looked at the association between CHM use and the likelihood of developing CKD, with a focus on usage intensity. Cases with CKD claims were defined and matched to one randomly selected control case. Conditional logistic regression was then applied to estimate odds ratio (OR) of CKD from CHM treatment measured before the index date. For each OR, we calculated a 95% confidence interval for CHM use relative to the matched control. Results
This nested case–control study included 5464 patients with RA, where after matching comprised 2712 cases and 2712 controls. Among them, there were 706 and 1199 cases that ever received CHM treatment, respectively. After the adjustment, CHM use in RA individuals was related to a lower likelihood of CKD, with an adjusted OR of 0.49 (95% CI: 0.44–0.56). Additionally, a dose-dependent, reverse association was found between the cumulative duration of CHM use and risk of CKD. Conclusion
Integrating CHM into conventional therapy may reduce the likelihood of developing CKD, which could be a reference in instituting novel preventive strategies to improve treatment outcomes and reduce related fatalities for RA subjects
AGE-BSA down-regulates endothelial connexin43 gap junctions
<p>Abstract</p> <p>Background</p> <p>Advanced glycation end products generated in the circulation of diabetic patients were reported to affect the function of vascular wall. We examined the effects of advanced glycation end products-bovine serum albumin (AGE-BSA) on endothelial connexin43 (Cx43) expression and gap-junction communication.</p> <p>Results</p> <p>In human aortic endothelial cells (HAEC) treated with a series concentrations of AGE-BSA (0-500 μg/ml) for 24 and 48 hours, Cx43 transcript and Cx43 protein were reduced in a dose dependent manner. In addition, gap-junction communication was reduced. To clarify the mechanisms underlying the down-regulation, MAPKs pathways in HAEC were examined. Both a MEK1 inhibitor (PD98059) and a p38 MAPK inhibitor (SB203580) significantly reversed the reductions of Cx43 mRNA and protein induced by AGE-BSA. Consistently, phosphorylation of ERK and p38 MAPK was enhanced in response to exposure to AGE-BSA. However, all reversions of down-regulated Cx43 by inhibitors did not restore the functional gap-junction communication.</p> <p>Conclusions</p> <p>AGE-BSA down-regulated Cx43 expression in HAEC, mainly through reduced Cx43 transcription, and the process involved activation of ERK and p38 MAPK.</p
Aberrant KDM5B expression promotes aggressive breast cancer through MALAT1 overexpression and downregulation of hsa-miR-448
Relative expression of KDM5B, MALAT1, SNAIL, Vimentin and miR 448 normalized against GAPDH in MCF10A WT, MCF10A OE, MDA-MB-231 WT and MDA-MB-231 KD cells. Data are representative of 3 independent experiments and analyzed by student’s t-test. All data are shown as mean ± SEM. WT, wild type; OE, KDM5B overexpressed; KD, knockdown using shKDM5B clone II. (DOCX 519 kb
The nucleolar protein NIFK promotes cancer progression via CK1α/β-catenin in metastasis and Ki-67-dependent cell proliferation.
Nucleolar protein interacting with the FHA domain of pKi-67 (NIFK) is a Ki-67-interacting protein. However, its precise function in cancer remains largely uninvestigated. Here we show the clinical significance and metastatic mechanism of NIFK in lung cancer. NIFK expression is clinically associated with poor prognosis and metastasis. Furthermore, NIFK enhances Ki-67-dependent proliferation, and promotes migration, invasion in vitro and metastasis in vivo via downregulation of casein kinase 1α (CK1α), a suppressor of pro-metastatic TCF4/β-catenin signaling. Inversely, CK1α is upregulated upon NIFK knockdown. The silencing of CK1α expression in NIFK-silenced cells restores TCF4/β-catenin transcriptional activity, cell migration, and metastasis. Furthermore, RUNX1 is identified as a transcription factor of CSNK1A1 (CK1α) that is negatively regulated by NIFK. Our results demonstrate the prognostic value of NIFK, and suggest that NIFK is required for lung cancer progression via the RUNX1-dependent CK1α repression, which activates TCF4/β-catenin signaling in metastasis and the Ki-67-dependent regulation in cell proliferation
Case report: Hemophagocytic lymphohistiocytosis complicated by multiple organ dysfunction syndrome following aseptic encephalitis
Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially life-threatening condition caused by excessive immune activation. Secondary HLH is usually triggered by infection, most often from viral infection or malignancy. Here, we present a case of secondary HLH, complicated by multiple organ dysfunction syndrome triggered by critical aseptic encephalitis. A 27-year-old man without any underlying disease presented to our hospital with fever, disturbance of consciousness, and generalized seizures. The patient was diagnosed with aseptic encephalitis with super-refractory status epilepticus. Although antiseizure medications and immunoglobulins were administered, the patient developed multiple organ dysfunction syndrome. HLH was later diagnosed based on hypertriglyceridemia, hyperferritinemia, splenomegaly, cytopenia, and phagocytosis of nucleated cells, as shown by a blood smear of bone marrow aspiration. Treatment with pulse steroid therapy and plasmapheresis was initiated rather than chemotherapy because of the patient’s critical condition. However, the patient died of profound shock and multiple organ failure. Diagnosis of HLH is challenging in patients with severe infections because of similar clinical manifestations and laboratory findings. The early recognition of HLH provides patients with the opportunity to receive appropriate treatment, which can lead to increased survival and remission rates
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